Display panel, electronic apparatus, and method of manufacturing display panel

ABSTRACT

An electronic apparatus includes: a display panel comprising a first display area, in which a first display element is arranged, and a second display area, in which a second display element and a transmission area are arranged; and a component on a lower surface of the display panel and overlapping the second display area, wherein the display panel includes: a substrate; a second pixel circuit on the substrate and electrically connected to the second display element, the second pixel circuit comprising at least one thin-film transistor; an organic insulating layer covering the at least one thin-film transistor; and a second transparent connection electrode on the organic insulating layer in the second display area and electrically connected to the second pixel circuit, wherein the second display element comprises a second pixel electrode on a same layer as the second transparent connection electrode.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority to and the benefit of KoreanPatent Application No. 10-2022-0038325, filed on Mar. 28, 2022, in theKorean Intellectual Property Office, the entire disclosure of which isincorporated herein by reference.

BACKGROUND 1. Field

Aspects of one or more embodiments relate to a display panel, anelectronic apparatus including the display panel, and a method ofmanufacturing the display panel.

2. Description of the Related Art

Recently, the various uses and applications of display panels hasdiversified. Also, display panels have become thinner and morelightweight, and thus, the use of display panels has generally expanded.

While increasing the area occupied by a display area in display panels,various functions have been incorporated into display panels. In orderto further increase the area and add various functions, studies havebeen conducted into a display device having, in the display area, anarea for adding various functions other than an image displayingfunction.

The above information disclosed in this Background section is only forenhancement of understanding of the background and therefore theinformation discussed in this Background section does not necessarilyconstitute prior art.

SUMMARY

Aspects of one or more embodiments include a display panel withrelatively improved reflective color bands, an electronic apparatusincluding the display panel, and a method of manufacturing the displaypanel.

Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the presented embodiments of the disclosure.

According to some embodiments, an electronic apparatus includes adisplay panel including a first display area, in which a first displayelement is arranged, and a second display area, in which a seconddisplay element and a transmission area are arranged, and a component ona lower surface of the display panel and overlapping the second displayarea, wherein the display panel includes a substrate, a second pixelcircuit on the substrate and electrically connected to the seconddisplay element, the second pixel circuit including at least onethin-film transistor, an organic insulating layer covering the at leastone thin-film transistor, and a second transparent connection electrodeon the organic insulating layer in the second display area andelectrically connected to the second pixel circuit, wherein the seconddisplay element including a second pixel electrode arranged on a samelayer as the second transparent connection electrode.

According to some embodiments, the second pixel electrode may include areflective material.

According to some embodiments, the second pixel electrode may cover oneend of the second transparent connection electrode.

According to some embodiments, the second pixel electrode may include afirst layer and a second layer on the first layer, the first layerincluding a reflective material and the second layer including atransparent conductive material.

According to some embodiments, the second transparent connectionelectrode may be arranged inside a via hole defined in the organicinsulating layer.

According to some embodiments, the second pixel electrode may include afirst layer including a reflective material and a third layer under thefirst layer, and the third layer may be integral with the secondtransparent connection electrode.

According to some embodiments, at least a portion of an edge of thesecond pixel electrode may have a round shape.

According to some embodiments, the electronic apparatus may furtherinclude a pixel defining layer having an opening exposing a center ofthe second pixel electrode and covering an edge of the second pixelelectrode, wherein the pixel defining layer may include a light blockingmaterial.

According to some embodiments, a display panel includes a substrate onwhich a first display element is, a first pixel circuit on the substrateand electrically connected to the first display element, the first pixelcircuit including at least one thin-film transistor, an organicinsulating layer covering the at least one thin-film transistor, and afirst transparent connection electrode on the organic insulating layerand electrically connected to the first pixel circuit, wherein the firstdisplay element includes a first pixel electrode arranged on a samelayer as the first transparent connection electrode.

According to some embodiments, the first pixel electrode may include afirst layer and a second layer on the first layer, the first layerincluding a reflective material and the second layer including atransparent conductive material, and the first transparent connectionelectrode may include a transparent conductive material.

According to some embodiments, the first transparent connectionelectrode may cover one end of the first pixel electrode.

According to some embodiments, the organic insulating layer may beprovided by sequentially stacking a first organic insulating layer, asecond organic insulating layer, and a third organic insulating layer,and the first transparent connection electrode may be connected to afirst connection electrode on the first organic insulating layer througha via hole.

According to some embodiments, the third organic insulating layer mayinclude a siloxane-based organic material.

According to some embodiments, at least a portion of an edge of thefirst pixel electrode may have a round shape.

According to some embodiments, the display panel may further include apixel defining layer having an opening exposing a center of the firstpixel electrode and covering an edge of the first pixel electrode,wherein the pixel defining layer may include a light blocking material.

According to some embodiments, a method of manufacturing a display panelincludes forming a first pixel circuit including at least one thin-filmtransistor on a substrate, forming a first organic insulating layercovering the at least one thin-film transistor, forming a secondconnection electrode on the first organic insulating layer, forming asecond organic insulating layer and a third organic insulating layercovering the second connection electrode and having a via hole exposinga portion of the second connection electrode, forming a secondtransparent connection electrode on the third organic insulating layerand connected to the second connection electrode through the via hole,and forming a second pixel electrode on the third organic insulatinglayer and covering one end of the second transparent connectionelectrode.

According to some embodiments, the second pixel electrode may include areflective material.

According to some embodiments, the second pixel electrode may include afirst layer and a second layer on the first layer, the first layerincluding a reflective material and the second layer including atransparent conductive material.

According to some embodiments, at least a portion of an edge of thesecond pixel electrode may have a round shape.

According to some embodiments, the method may further include forming apixel defining layer having an opening exposing a center of the secondpixel electrode and covering an edge of the second pixel electrode,wherein the pixel defining layer includes a light blocking material.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and characteristics of certainembodiments of the disclosure will be more apparent from the followingdescription taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a perspective view illustrating an electronic apparatusaccording to some embodiments;

FIG. 2 is a cross-sectional view schematically illustrating a portion ofa cross-section of an electronic apparatus, according to someembodiments;

FIG. 3 is an equivalent circuit diagram of a pixel circuit configured todrive a sub-pixel, according to some embodiments;

FIG. 4 is a layout diagram schematically illustrating a pixelarrangement structure in a first display area, according to someembodiments;

FIG. 5 is a layout diagram schematically illustrating a pixelarrangement structure in a second display area, according to someembodiments;

FIG. 6 is a schematic cross-sectional view illustrating a portion of adisplay panel, according to some embodiments;

FIG. 7 is a schematic cross-sectional view illustrating a portion of adisplay panel, according to some embodiments;

FIG. 8 is a schematic cross-sectional view illustrating a portion of adisplay panel, according to some embodiments;

FIG. 9 is a schematic cross-sectional view illustrating a portion of adisplay panel, according to some embodiments;

FIG. 10 is a plan layout diagram illustrating an auxiliary sub-pixel ofa display device, according to some embodiments; and

FIGS. 11A to 11D are cross-sectional views sequentially illustrating amethod of manufacturing a display panel, according to some embodiments.

DETAILED DESCRIPTION

Reference will now be made in more detail to aspects of someembodiments, which are illustrated in the accompanying drawings, whereinlike reference numerals refer to like elements throughout. In thisregard, the present embodiments may have different forms and should notbe construed as being limited to the descriptions set forth herein.Accordingly, the embodiments are merely described below, by referring tothe figures, to explain aspects of the present description. As usedherein, the term “and/or” includes any and all combinations of one ormore of the associated listed items. Throughout the disclosure, theexpression “at least one of a, b or c” indicates only a, only b, only c,both a and b, both a and c, both b and c, all of a, b, and c, orvariations thereof.

As the present description allows for various changes and numerousembodiments, certain embodiments will be illustrated in the drawings anddescribed in detail in the written description. Effects and features ofthe disclosure, and methods of achieving them will be clarified withreference to embodiments described below in detail with reference to thedrawings. However, the disclosure is not limited to the followingembodiments and may be embodied in various forms.

Hereinafter, aspects of some embodiments will be described in moredetail with reference to the accompanying drawings. When describingembodiments with reference to the accompanying drawings, the same orcorresponding elements are denoted by the same reference numerals.

It will be understood that although the terms “first,” “second” etc. maybe used herein to describe various elements, these elements should notbe limited by these terms. These terms are only used to distinguish oneelement from another.

The singular forms “a,” “an,” and “the” as used herein are intended toinclude the plural forms as well unless the context clearly indicatesotherwise.

It will be further understood that the terms “include” and/or “comprise”used herein specify the presence of stated features or elements, but donot preclude the presence or addition of one or more other features orelements.

It will be further understood that, when a layer, region, or element isreferred to as being “on” another layer, region, or element, it may bedirectly or indirectly on the other layer, region, or element. That is,for example, intervening layers, regions, or elements may be present.

In the following embodiments, the expression “at least one of A and B”indicates only A, only B, or both A and B.

Also, sizes of elements in the drawings may be exaggerated or reducedfor convenience of explanation. For example, because sizes andthicknesses of elements in the drawings are arbitrarily illustrated forconvenience of explanation, the disclosure is not limited thereto.

When a certain embodiment may be implemented differently, a specificprocess order may be performed differently from the described order. Forexample, two consecutively described processes may be performedsubstantially at the same time or performed in an order opposite to thedescribed order.

It will be further understood that, when layers, regions, or elementsare referred to as being connected to each other, they may be directlyconnected to each other or indirectly connected to each other withintervening layers, regions, or elements therebetween. For example, whenlayers, regions, or elements are referred to as being electricallyconnected to each other, they may be directly electrically connected toeach other or indirectly electrically connected to each other withintervening layers, regions, or elements therebetween.

FIG. 1 is a perspective view illustrating an electronic apparatus 1according to some embodiments.

The electronic apparatus 1 according to some embodiments is configuredto display a moving (e.g., video) image or a still (e.g., static) image.The electronic apparatus 1 may be used as display screens of portableelectronic apparatuses, such as mobile phones, smartphones, tabletpersonal computers (PCs), mobile communication terminals, electronicorganizers, e-books, portable multimedia players (PMPs), navigations,and ultra mobile PCs (UMPCs). Also, the electronic apparatus 1 may beused as display screens of various products, such as televisions,laptops, monitors, billboards, and Internet of things (IoT) devices.Also, the electronic apparatus 1 according to some embodiments may beused in wearable devices, such as smart watches, watch phones,glass-type displays, and head mounted displays (HMDs). Also, theelectronic apparatus 1 according to some embodiments may be used indashboards of automobiles, center information displays (CIDs) on thecenter fascia or dashboards of automobiles, room mirror displaysreplacing side mirrors of automobiles, and displays on the rear sides offront seats to serve as entertainment devices for backseat passengers ofautomobiles. For convenience of description, FIG. 1 illustrates that theelectronic apparatus 1 is used as a smartphone.

Referring to FIG. 1 , the electronic apparatus 1 may include a displayarea DA and a non-display area NDA outside (e.g., outside a footprint orin a periphery of) the display area DA. The electronic apparatus 1 mayprovide an image through an array of pixels that are two-dimensionallyarranged in the display area DA.

The non-display area NDA is an area that does not provide or displayimages and may completely surround the display area DA. A driver or thelike that provides electrical signals or power to display elementsarranged in the display area DA may be arranged in the non-display areaNDA. A pad, which is an area to which an electronic element or a printedcircuit board may be electrically connected, may be arranged in thenon-display area NDA.

The display area DA may include a first display area DA1 and a seconddisplay area DA2. The second display area DA2 is an area in whichcomponents for adding various functions to the electronic apparatus 1are arranged, and the second display area DA2 may correspond to acomponent area. As illustrated in FIG. 1 , the second display area DA2may be arranged inside the first display area DA1 and surrounded by thefirst display area DA1. According to some embodiments, the seconddisplay area DA2 may be arranged on one side of the first display areaDA1 and may be arranged between the first display area DA1 and thenon-display area NDA. A plurality of second display areas DA2 may beprovided. In this case, components may be respectively arranged tocorrespond to the second display areas DA2.

FIG. 2 is a cross-sectional view schematically illustrating a portion ofa cross-section of an electronic apparatus 1, according to someembodiments. For example, FIG. 2 illustrates a portion in which firstdisplay areas DA1 are arranged on both sides of a second display areaDA2.

Referring to FIG. 2 , the electronic apparatus 1 may include a displaypanel and a component 40 located under the display panel 10 to overlapthe display panel 10. The component 40 may overlap the second displayarea DA2. The electronic apparatus 1 may further include a cover window50 located on the display panel 10 to protect the display panel 10.

The display panel 10 includes the second display area DA2 which overlapsthe component 40, and the first display areas DA1 on which a main imageis displayed. The display panel 10 may include a substrate 100, adisplay layer DISL, a touch screen layer TSL, an optical function layerOFL, and a panel protection member PB. The display layer DISL, the touchscreen layer TSL, and the optical function layer OFL may be located onthe substrate 100, and the panel protection member PB may be locatedunder the substrate 100.

The display layer DISL may include a circuit layer PCL including firstand second thin-film transistors TFT and TFT′, a display element layerincluding a main light-emitting device ED and an auxiliarylight-emitting device ED′ as a display element, and an encapsulationmember ENCM, such as a thin-film encapsulation layer TFEL or anencapsulation substrate. Insulating layers IL and IL′ may be arrangedbetween the substrate 100 and the display layer DISL and may be arrangedin the display layer DISL.

The substrate 100 may include an insulating material, such as a polymerresin. The substrate 100 may be a bendable, foldable, rollable, flexiblesubstrate. The substrate 100 may have a multilayer structure includingan inorganic layer and a layer including a polymer resin.

The first thin-film transistor TFT and the main light-emitting device EDconnected thereto may be arranged in the first display area DA1 of thedisplay panel to implement a main sub-pixel Pm, and the second thin-filmtransistor TFT′ and the auxiliary light-emitting device ED′ connectedthereto may be arranged in the second display area DA2 to implement anauxiliary sub-pixel Pa.

The main light-emitting device ED and the auxiliary light-emittingdevice ED′ may be organic light-emitting diodes including an organicmaterial. The organic light-emitting diode may emit red light, greenlight, or blue light. The first and second light-emitting devices ED andED′ may each be an inorganic light-emitting diode including an inorganicmaterial. The inorganic light-emitting diode may include a PN junctiondiode including inorganic semiconductor-based materials. When a voltageis applied to the PN junction diode in a forward direction, holes andelectrons are injected and recombined to generate energy, and the energyis converted into light energy to emit light of a certain color. Theinorganic light-emitting diode may have a width of several to severalhundred micrometers or several to several hundred nanometers. In someembodiments, the first and second light-emitting devices ED and ED′ mayeach include a quantum dot light-emitting diode. Emission layers of thefirst and second light-emitting devices ED and ED′ may each include anorganic material, an inorganic material, quantum dots, an organicmaterial and quantum dots, or an inorganic material and quantum dots.

A transmission area TA in which no display element is arranged may bearranged in the second display area DA2. The transmission area TA may bean area through which light or a signal emitted from the component 40arranged to correspond to the second display area DA2 or light or asignal incident on the component 40 may be transmitted. In the displaypanel 10, the transmittance of the transmission area TA may be about 30%or more, about 40% or more, about 50% or more, about 60% or more, about70% or more, about 75% or more, about 80% or more, about 85% or more, orabout 90% or more.

The component 40 may include a camera (or an image sensor) and a sensor,such as a proximity sensor, an illumination sensor, an iris sensor, or afacial recognition sensor. The component 40 may use light. For example,the component 40 may emit and/or receive light in infrared, ultraviolet,and visible light bands. The proximity sensor using infrared light maydetect an object located close to the upper surface of the electronicapparatus 1, and the illumination sensor may detect the brightness oflight incident on the upper surface of the electronic apparatus 1. Also,the iris sensor may photograph an iris of a person located above theelectronic apparatus 1, and the camera may receive light related to anobject located above the electronic apparatus 1.

A bottom metal layer BML may be arranged in the second display area DA2.The bottom metal layer BML may be arranged to correspond to the lowerportion of the second thin-film transistor TFT′. For example, the bottommetal layer BML may be between the second thin-film transistor TFT′ andthe substrate 100. The bottom metal layer BML may prevent or reduceexternal light reaching the second thin-film transistor TFT′. Accordingto some embodiments, a constant voltage or a signal may be applied tothe bottom metal layer BML to prevent or reduce damage to the pixelcircuit due to electrostatic discharge.

The display element layer EDL may be covered with the thin-filmencapsulation layer TFEL or the encapsulation substrate. In someembodiments, the thin-film encapsulation layer TFEL may include at leastone inorganic encapsulation layer and at least one organic encapsulationlayer, as illustrated in FIG. 2 . According to some embodiments, thethin-film encapsulation layer TFEL may include first and secondinorganic encapsulation layers 131 and 133 and an organic encapsulationlayer 132 therebetween.

The first and second inorganic encapsulation layers 131 and 133 mayinclude at least one inorganic insulating material selected from siliconoxide, silicon nitride, and silicon oxynitride. The organicencapsulation layer 340 may include a polymer-based material. Thepolymer-based material may include an acrylic resin, an epoxy resin,polyimide, polyethylene, and the like.

When the display element layer EDL is sealed with the encapsulationsubstrate, the encapsulation substrate may be arranged to face thesubstrate 100 with the display element layer EDL therebetween. A gap mayexist between the encapsulation substrate and the display element layerEDL. The encapsulation substrate may include glass. A sealant includingfrit or the like may be between the substrate 100 and the encapsulationsubstrate, and the sealant may be arranged in the non-display area NDAdescribed above. The sealant arranged in the non-display area NDA mayprevent or reduce instances of moisture or other contaminantspenetrating through the side surface of the electronic apparatus 1 whilesurrounding the display area DA.

The touch screen layer TSL may be configured to obtain coordinateinformation according to an external input, for example, a touch event.The touch screen layer TSL may include touch electrodes and touch linesconnected to the touch electrodes. The touch screen layer TSL may sensean external input by using a self-capacitance method or a mutualcapacitance method.

The touch screen layer TSL may be located on the thin-film encapsulationlayer TFEL. Alternatively, the touch screen layer TSL may be separatelyformed on a touch substrate and then connected to the thin-filmencapsulation layer TFEL through an adhesive layer, such as an opticallyclear adhesive. According to some embodiments, the touch screen layerTSL may be formed directly on the thin-film encapsulation layer TFEL. Inthis case, the adhesive layer may not be formed or utilized between thetouch screen layer TSL and the thin-film encapsulation layer TFEL.

The optical function layer OFL may be introduced in order to improvevisibility. The optical function layer OFL may include, for example, ananti-reflection layer. The anti-reflection layer may reduce thereflectance of light (external light) incident from the outside towardthe electronic apparatus 1.

According to some embodiments, the anti-reflection layer may include apolarizing film. In some embodiments, the anti-reflection layer mayinclude a filter layer including a black matrix and color filters. Thecolor filters may be arranged considering the color of light emittedfrom each pixel of the electronic apparatus 1. For example, the colorfilters may include a red, green, or blue color filter.

According to some embodiments, the anti-reflection layer may include adestructive interference structure. The destructive interferencestructure may include a first reflective layer and a second reflectivelayer located on different layers from each other. First reflected lightand second reflected light respectively reflected from the firstreflective layer and the second reflective layer may destructivelyinterfere with each other, and thus, the reflectance of external lightmay be reduced.

The cover window 50 may be located on the display panel 10 to protectthe display panel 10. The cover window 50 may include a glass materialor a plastic material. The glass material may include ultra-thin glass.The plastic material may include polyethersulfone, polyacrylate,polyether imide, polyethylene naphthalate, polyethylene terephthalate,polyphenylene sulfide, polyarylate, polyimide, polycarbonate, orcellulose acetate propionate. The optical function layer OFL may bebonded to the cover window with an optically clear adhesive, or may bebonded to the touch screen layer TSL with an optically clear adhesive.

The panel protection member PB may be bonded to the lower portion of thesubstrate 100 to support and protect the substrate 100. The panelprotection member PB may include an opening PB_OP corresponding to thesecond display area DA2. By providing the opening PB_OP in the panelprotection member PB, the light transmittance of the second display areaDA2 may be improved. The panel protection cover PB may includepolyethylene terephthalate (PET) or polyimide (PI).

The area of the second display area DA2 may be greater than the area inwhich the component 40 is arranged. Accordingly, the area of the openingPB_OP provided in the panel protection member PB may not coincide withthe area of the second display area DA2.

Also, a plurality of components 40 may be arranged in the second displayarea DA2. The components 40 may have different functions from eachother. For example, the components 40 may include at least two of acamera (imaging device), a solar cell, a flash, a proximity sensor, anillumination sensor, and an iris sensor.

FIG. 3 is an equivalent circuit diagram of a pixel circuit PC configuredto drive a sub-pixel, according to some embodiments.

Referring to FIG. 3 , the pixel circuit PC may be connected to alight-emitting device ED to implement light emission of sub-pixels. Thepixel circuit PC includes a driving thin-film transistor T1, a switchingthin-film transistor T2, and a storage capacitor Cst. The switchingthin-film transistor T2 is connected to a scan line SL and a data lineDL, and may be configured to transmit, to the driving thin-filmtransistor T1, a data signal Dm input through the data line DL inresponse to a scan signal Sn input through the scan line SL.

The storage capacitor Cst is connected to the switching thin-filmtransistor T2 and a driving voltage line PL, and may be configured tostore a voltage corresponding to a difference between a voltage receivedfrom the switching thin-film transistor T2 and a driving voltage ELVDDsupplied to the driving voltage line PL.

The driving thin-film transistor T1 may be connected to the drivingvoltage line PL and the storage capacitor Cst, and may be configured tocontrol a driving current flowing from the driving voltage line PL tothe light-emitting device ED according to a voltage value stored in thestorage capacitor Cst. The light-emitting device ED may emit lighthaving a certain luminance according to the driving current.

Although FIG. 3 illustrates that the circuit PC includes two thin-filmtransistors and one storage capacitor, embodiments according to thepresent disclosure are not limited thereto. The pixel circuit PC,however, may be variously modified. For example, the pixel circuit PCmay include three or more thin-film transistors and/or two or morestorage capacitors. That is, in various embodiments, the pixel circuitPC may include additional components, or fewer components, withoutdeparting from the spirit and scope of embodiments according to thepresent disclosure.

FIG. 4 is a layout diagram schematically illustrating a pixelarrangement structure in a first display area DA1, according to someembodiments.

A plurality of main sub-pixels Pm may be arranged in the first displayarea DA1. In the present specification, the sub-pixel is a minimum unitfor implementing an image and refers to an emission area. On the otherhand, when an organic light-emitting diode is employed as a displayelement, the emission area may be defined by an opening of a pixeldefining layer. This will be described in more detail below.

As illustrated in FIG. 4 , the main sub-pixels Pm in the first displayarea DA1 may be arranged in a PenTile™ structure. The main sub-pixels Pmmay include a first sub-pixel Pr, a second sub-pixel Pg, and a thirdsub-pixel Pb, which may implement red, green, and blue, respectively.

In a first row 1N, first sub-pixels Pr and third sub-pixels Pb arealternately arranged. In a second row 2N adjacent to the first row 1N,second sub-pixels Pg are apart from each other at certain intervals. Ina third row 3N adjacent to the second row 2N, third sub-pixels Pb andfirst sub-pixels Pr are alternately arranged. In a fourth row 4Nadjacent to the third row 3N, second sub-pixels Pg are apart from eachother at certain intervals. Such a pixel arrangement is repeated up toan N^(th) row. In this case, the third sub-pixel Pb and the firstsub-pixel Pr may be greater than the second sub-pixel Pg.

The first sub-pixels Pr and the third sub-pixels Pb in the first row 1Nmay be misaligned with the second sub-pixels Pg in the second row 2N.Therefore, in a first column 1M, the first sub-pixels Pr and the thirdsub-pixels Pb are alternately arranged. In a second column 2M adjacentto the first column 1M, the second sub-pixels Pg are apart from eachother at certain intervals. In a third column 3M adjacent to the secondcolumn 2M, the third sub-pixels Pb and the first sub-pixels Pr arealternately arranged. In a fourth column 4M adjacent to the third column3M, the second sub-pixels Pg are apart from each other at certainintervals. Such a pixel arrangement is repeated up to an M^(th) column.

Such a pixel array structure is expressed differently as follows: in avirtual quadrangle VS having the center point of the second sub-pixel Pgas the center point of the virtual quadrangle VS, the first sub-pixelsPr are arranged at the first and third vertices of the virtualquadrangle VS facing each other, and the third sub-pixels Pb arearranged at the remaining second and fourth vertices of the virtualquadrangle VS. In this case, the virtual quadrangle VS may be variouslymodified into, for example, a rectangle, a rhombus, and a square.

Such a pixel array structure is called a Pentile™ matrix structure or aPentile™ structure, and may implement high resolution with a smallnumber of pixels by applying a rendering driving that shares adjacentpixels to express colors.

FIG. 4 illustrates that the main sub-pixels Pm are arranged in aPentile™ matrix structure, but the disclosure is not limited thereto.For example, the main sub-pixels Pm may be arranged in various forms,for example, a stripe structure, a mosaic array structure, and a deltaarray structure.

FIG. 5 is a layout diagram schematically illustrating a pixelarrangement structure in a second display area DA2, according to someembodiments.

Referring to FIG. 5 , a plurality of auxiliary sub-pixels Pa may bearranged in the second display area DA2. The auxiliary sub-pixels Pa mayeach emit one of red light, green light, blue light, and white light.

The second display area DA2 may have a pixel group PG including at leastone auxiliary sub-pixel Pa and a transmission area TA. The pixel groupPG and the transmission area TA are alternately arranged in thex-direction and the y-direction, and may be arranged in, for example, agrid shape. In this case, the second display area DA2 may have aplurality of pixel groups PG and a plurality of transmission areas TA.

The pixel group PG may be defined as a sub-pixel assembly in which aplurality of auxiliary sub-pixels Pa are grouped into a preset unit. Forexample, as illustrated in FIG. 5 , one pixel group PG may include eightauxiliary sub-pixels Pa arranged in a Pentile™ structure. That is, onepixel group PG may include two first sub-pixels Pr′, four secondsub-pixels Pg′, and two third sub-pixels Pb′.

In the second display area DA2, a basic unit U in which a certain numberof pixel groups PG and a certain number of transmission areas TA aregrouped may be repeatedly arranged in the x-direction and they-direction. In FIG. 5 , the basic unit U may have a shape in which twopixel groups PG and two transmission areas TA arranged around the twopixel groups PG are grouped into a rectangle. The basic unit U is adivision of a repetitive shape, and does not mean a discontinuity instructure.

A corresponding unit U′ having the same area as the area of the basicunit U may be set in the first display area DA1. In this case, thenumber of main sub-pixels Pm included in the corresponding unit U′ maybe greater than the number of auxiliary sub-pixels Pa included in thebasic unit U. 16 auxiliary sub-pixels Pa may be included in the basicunit U, and 32 main sub-pixels Pm may be included in the correspondingunit U′. That is, a ratio of the number of auxiliary sub-pixels Pa tothe number of main sub-pixels Pm may be 1:2 in the same area.

The pixel arrangement structure of the second display area DA2 in whichthe auxiliary sub-pixels Pa are arranged in Pentile™ structure, asillustrated in FIG. 5 , and the resolution of the second display areaDA2 is half the resolution of the first display area DA1 is called a ½Pentile™ structure. The design in the number or arrangement of theauxiliary sub-pixels Pa included in the pixel group PG may be modifiedaccording to the resolution of the second display area DA2.

FIGS. 6 and 7 are schematic cross-sectional views illustrating a portionof a display panel 10, according to some embodiments. For example, FIG.6 is a cross-sectional view schematically illustrating a portion of afirst display area DA1, and FIG. 7 is a cross-sectional viewschematically illustrating a portion of a second display area DA2.

Referring to FIGS. 6 and 7 , the display panel 10 includes the firstdisplay area DA1 and the second display area DA2. A main sub-pixel Pm isarranged in the first display area DA1, and an auxiliary sub-pixel Pa isarranged in the second display area DA2. The second display area DA2 hasa transmission area TA. A main pixel circuit PC and a first organiclight-emitting diode OLED may be arranged in the first display area DA1.The main pixel circuit PC includes a first thin-film transistor TFT anda first storage capacitor Cst. The first organic light-emitting diodeOLED is a display element connected to the main pixel circuit PC. Anauxiliary pixel circuit PC′ and a second organic light-emitting diodeOLED′ may be arranged in the second display area DA2. The auxiliarypixel circuit PC′ includes a second thin-film transistor TFT′ and asecond storage capacitor Cst′. The second organic light-emitting diodeOLED′ is a display element connected to the auxiliary pixel circuit PC′.

According to some embodiments, the case where the organic light-emittingdiode is employed as the display element is described as an example, butaccording to some embodiments, an inorganic light-emitting device or aquantum dot light-emitting device may be employed as the displayelement.

Hereinafter, a structure in which elements included in the display panel10 are stacked will be described in more detail. The display panel 10may be provided by stacking a substrate 100, a buffer layer 111, pixelcircuits PC and PC′, organic light-emitting diodes OLED and OLED′, and athin-film encapsulation layer TFEL.

The substrate 100 may include an insulating material, such as a polymerresin. The substrate 100 may be a bendable, foldable, rollable, flexiblesubstrate. The substrate 100 may include a structure in which an organicmaterial, an inorganic material, and an organic material are stacked.

The buffer layer 111 may be located on the substrate 100 to reduce orprevent infiltration of foreign material, moisture, or ambient air frombelow the substrate 100, and may provide a flat surface on the substrate100. The buffer layer 111 may include an inorganic material, such as anoxide or a nitride, an organic material, or an organic/inorganiccomposite material, and may have a single-layer or multilayer structureincluding an inorganic material and an organic material. A barrier layerthat prevents or reduces infiltration of ambient air may be furtherincluded between the substrate 100 and the buffer layer 111. Accordingto some embodiments, the buffer layer 111 may include silicon oxide(SiO_(x)) or silicon nitride (SiN_(x)). According to some embodiments,the buffer layer 111 may be provided by stacking silicon oxide (SiO_(x))and silicon nitride (SiN_(x)).

In the second display area DA2, a bottom metal layer BML may be betweenthe substrate 100 and the buffer layer 111. The bottom metal layer BMLis located under the auxiliary pixel circuit PC′ to prevent or reducecharacteristics of the second thin-film transistor TFT′ from beingdeteriorated due to light emitted from a component or the like. Also,the bottom metal layer BML may prevent or reduce light emitted from ordirected to the component or the like diffracting through a narrow gapbetween wirings connected to the auxiliary pixel circuit PC′. The bottommetal layer BML may include a lower hole BMLH corresponding to thetransmission area TA.

A bias voltage may be applied to the bottom metal layer BML. Because thebias voltage is applied to the bottom metal layer BML, the bottom metallayer BML may significantly reduce the probability that electrostaticdischarge will occur. The bottom metal layer BML may include aluminum(Al), platinum (Pt), palladium (Pd), silver (Ag), magnesium (Mg), gold(Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), calcium(Ca), molybdenum (Mo), titanium (Ti), tungsten (W), and/or copper (Cu).The bottom metal layer BML may include a single layer or layersincluding the material described above.

The pixel circuits PC and PC′ may be located on the buffer layer 111.The main pixel circuit PC may include the first thin-film transistor TFTand the first storage capacitor Cst, and the auxiliary pixel circuit PC′may include the second thin-film transistor TFT′ and the second storagecapacitor Cst′.

The first thin-film transistor TFT and the second thin-film transistorTFT′ may be located on the buffer layer 111. The first thin-filmtransistor TFT includes a first semiconductor layer A1, a first gateelectrode G1, a first source electrode S1, and a first drain electrodeD1, and the second thin-film transistor TFT includes a secondsemiconductor layer A2, a second gate electrode G2, a second sourceelectrode S2, and a second drain electrode D2. The first thin-filmtransistor TFT may be connected to the first organic light-emittingdiode OLED and configured to drive the first organic light-emittingdiode OLED. The second thin-film transistor TFT′ may be connected to thesecond organic light-emitting diode OLED′ and configured to drive thesecond organic light-emitting diode OLED′.

The first semiconductor layer A1 and the second semiconductor layer A2may be located on the buffer layer 111, and may include polysilicon.According to some embodiments, the first semiconductor layer A1 and thesecond semiconductor layer A2 may include amorphous silicon. Accordingto some embodiments, the first semiconductor layer A1 and the secondsemiconductor layer A2 may include an oxide of at least one selectedfrom indium (In), gallium (Ga), stannum (Sn), zirconium (Zr), vanadium(V), hafnium (Hf), cadmium (Cd), germanium (Ge), chromium (Cr), titanium(Ti), and zinc (Zn). The first semiconductor layer A1 and the secondsemiconductor layer A2 may each include a channel region, and a sourceregion and a drain region doped with impurities.

The second semiconductor layer A2 may overlap the bottom metal layer BMLwith the buffer layer 111 therebetween. According to some embodiments,the width of the second semiconductor layer A2 may be less than thewidth of the bottom metal layer BML. Accordingly, when projected in adirection perpendicular to the substrate 100, the second semiconductorlayer A2 may completely overlap the bottom metal layer BML.

A first gate insulating layer 112 may be provided to cover the firstsemiconductor layer A1 and the second semiconductor layer A2. The firstgate insulating layer 112 may include an inorganic insulating material,such as silicon oxide (SiO_(x)), silicon nitride (SiN_(x)), siliconoxynitride (SiON), aluminum oxide (Al₂O₃), titanium oxide (TiO₂),tantalum oxide (Ta₂O₅), or hafnium oxide (HfO₂). The first gateinsulating layer 112 may include a single layer or layers including theinorganic insulating material described above.

The first gate electrode G1 and the second gate electrode G2 are locatedon the first gate insulating layer 112 to overlap the firstsemiconductor layer A1 and the second semiconductor layer A2,respectively. The first gate electrode G1 and the second gate electrodeG2 may include molybdenum (Mo), aluminum (Al), copper (Cu), titanium(Ti), and the like, and may include a single layer or layers. Forexample, the first gate electrode G1 and the second gate electrode G2may each be a single Mo layer.

The second gate insulating layer 113 may cover the first gate electrodeG1 and the second gate electrode G2. The second gate insulating layer113 may include an inorganic insulating material, such as silicon oxide(SiO_(x)), silicon nitride (SiN_(x)), silicon oxynitride (SiON),aluminum oxide (Al₂O₃), titanium oxide (TiO₂), tantalum oxide (Ta₂O₅),or hafnium oxide (HfO₂). The second gate insulating layer 113 mayinclude a single layer or layers including the inorganic insulatingmaterial described above.

A first upper electrode CE2 of the first storage capacitor Cst and asecond upper electrode CE2′ of the second storage capacitor Cst′ may belocated above the second gate insulating layer 113.

In the first display area DA1, the first upper electrode CE2 may overlapthe first gate electrode G1 therebelow. The first gate electrode G1 andthe first upper electrode CE2 overlapping each other with the secondgate insulating layer 113 therebetween may constitute the first storagecapacitor Cst. The first gate electrode G1 may be the first lowerelectrode CE1 of the first storage capacitor Cst.

In the second display area DA2, the second upper electrode CE2′ mayoverlap the second gate electrode G2 therebelow. The second gateelectrode G2 and the second upper electrode CE2′ overlapping each otherwith the second gate insulating layer 113 therebetween may constitutethe second storage capacitor Cst′.

The second gate electrode G2 may be the second lower electrode CE1′ ofthe second storage capacitor Cst′.

The first upper electrode CE2 and the second upper electrode CE2′ mayinclude aluminum (Al), platinum (Pt), palladium (Pd), silver (Ag),magnesium (Mg), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir),chromium (Cr), calcium (Ca), molybdenum (Mo), titanium (Ti), tungsten(Ti), and/or copper (Cu), and may include a single layer or layersincluding the material described above.

An interlayer insulating layer 115 may be arranged to cover the firstupper electrode CE2 and the second upper electrode CE2′. The interlayerinsulating layer 115 may include silicon oxide (SiO_(x)), siliconnitride (SiN_(x)), silicon oxynitride (SiON), aluminum oxide (Al₂O₃),titanium oxide (TiO₂), tantalum oxide (Ta₂O₅), hafnium oxide (HfO₂). Theinterlayer insulating layer 115 may include a single layer or layersincluding the inorganic insulating material described above.

When the first gate insulating layer 112, the second gate insulatinglayer 113, and the interlayer insulating layer 115 are collectivelyreferred to as an inorganic insulating layer IL, the inorganicinsulating layer IL may have a first hole H1 corresponding to thetransmission area TA. The first hole H1 may expose a portion of thebuffer layer 111 or the upper surface of the substrate 100. The firsthole H1 may be defined by overlapping an opening of the first gateinsulating layer 112, an opening of the second gate insulating layer113, and an opening of the interlayer insulating layer 115, which areformed to correspond to the transmission area TA. These openings may beseparately formed through separate processes, or may be simultaneouslyformed through the same process. When these openings are formed throughseparate processes, the inner surface of the first hole H1 may not besmooth and may have a step, such as a stair shape.

On the other hand, according to some embodiments, the buffer layer 111may have a buffer hole H0 corresponding to the transmission area TA. Thebuffer hole H0 may expose a portion of the upper surface of thesubstrate 100. The area of the buffer hole H0 may be less than the areaof the first hole H1. Because the buffer layer 111 and the inorganicinsulating layer IL have the first hole H1 and the buffer hole H0corresponding to the transmission area TA, the light transmittance ofthe second display area DA2 may be improved.

A first wiring WL1, the source electrodes S1 and S2, and the drainelectrodes D1 and D2 may be located on the interlayer insulating layer115. The first wiring WL1 may be configured to transmit a data signal ora driving voltage to the pixel circuit PC. The first wiring WL1, thesource electrodes S1 and S2, and the drain electrodes D1 and D2 mayinclude a conductive material including molybdenum (Mo), aluminum (Al),copper (Cu), titanium (Ti), and the like, and may include a single layeror layers including the conductive material described above. Forexample, the first wiring WL1, the source electrode S1 and S2, and thedrain electrodes D1 and D2 may have a multilayer structure of Ti/Al/Ti.

An organic insulating layer OL may be arranged to cover the firstthin-film transistor TFT and the second thin-film transistor TFT′. Theorganic insulating layer OL may include a single layer or layers. Forexample, the organic insulating layer OL may be provided by stacking afirst organic insulating layer 116, a second organic insulating layer117, and a third organic insulating layer 118. In this case, a secondwiring WL2 may be located on the first organic insulating layer 116, anda third wiring WL3 may be located on the second organic insulating layer117. The second wiring WL2 and the third wiring WL3 may be configured totransmit various signals and/or voltages to the pixel circuits PC andPC′.

The first organic insulating layer 116 may be arranged to cover thefirst wiring WL1, the source electrodes S1 and S2, and the drainelectrodes D1 and D2. The first organic insulating layer 116 may includegeneral-purpose polymer (e.g., photosensitive polyimide, polyimide,polystyrene (PS), polycarbonate (PC), benzocyclobutene (BCB),hexamethyldisiloxane (HMDSO), or polymethylmethacrylate (PMMA)), polymerderivatives having a phenolic group, acrylic polymer, imide-basedpolymer, aryl ether-based polymer, amide-based polymer, fluorine-basedpolymer, p-xylene-based polymer, or vinyl alcohol-based polymer.

Connection electrodes CM and CM′ and the second wiring WL2 may belocated on the first organic insulating layer 116. The connectionelectrodes CM and CM′ may be members that electrically connect the pixelcircuits PC and PC′ to the organic light-emitting diodes OLED and OLED′.The connection electrodes CM and CM′ may be connected to one or morethin-film transistor TFT and TFT′ through via holes VH1 and VH1′ passingthrough the first organic insulating layer 116. The second wiring WL2may overlap the first wiring WL1. As the second wiring WL2 is provided,the display panel may be highly integrated.

The connection electrodes CM and CM′ and the second wiring WL2 mayinclude a conductive material including molybdenum (Mo), aluminum (Al),copper (Cu), titanium (Ti), and the like, and may include a single layeror layers including the conductive material described above.

The second organic insulating layer 117 may be arranged to cover theconnection electrodes CM and CM′ and the second wiring WL2. The secondorganic insulating layer 117 may include the same material as that ofthe first organic insulating layer 116. The second organic insulatinglayer 117 may include general-purpose polymer (e.g., photosensitivepolyimide, polyimide, PS, PC, BCB, HMDSO, or PMMA), polymer derivativeshaving a phenolic group, acrylic polymer, imide-based polymer, arylether-based polymer, amide-based polymer, fluorine-based polymer,p-xylene-based polymer, or vinyl alcohol-based polymer.

The third wiring WL3 may be located on the second organic insulatinglayer 117. The third wiring WL3 may include the same material as that ofthe first wiring WL1 and/or the second wiring WL2, and may overlap thefirst wiring WL1 and/or the second wiring WL2.

The third organic insulating layer 118 may be located on the secondorganic insulating layer 117 to cover the third wiring WL3. The thirdorganic insulating layer 118 may have a flat upper surface so that afirst pixel electrode 121 and a second pixel electrode 121′ locatedthereon are formed to be flat. A first transparent connection electrodeTCM connected to the first pixel electrode 121 and a second transparentconnection electrode TCM′ connected to the second pixel electrode 121′may be located on the upper surface of the third organic insulatinglayer 118.

In some embodiments, the third organic insulating layer 118 may includea material that is different from a material of each of the firstorganic insulating layer 116 and the second organic insulating layer117. The third organic insulating layer 118 may include an organicmaterial having an upper surface flatness better than that of the firstorganic insulating layer 116 and the second organic insulating layer117. For example, the third organic insulating layer 118 may include asiloxane-based organic material. The siloxane-based organic material mayinclude hexamethyldisiloxane, octamethyltrisiloxane,decamethyltetrasiloxane, dodecamethylpentasiloxane, andpolydimethylsiloxane.

According to some embodiments, the first organic insulating layer 116,the second organic insulating layer 117, and the third organicinsulating layer 118 may all include the same material. For example, thefirst organic insulating layer 116, the second organic insulating layer117, and the third organic insulating layer 118 may all include thesiloxane-based organic material.

Because the third organic insulating layer 118 include an organicmaterial having a high flatness, the first pixel electrode 121 and thesecond pixel electrode 121′ located on the third organic insulatinglayer 118 may be provided to be flat. Therefore, interference betweenpieces of light reflected from the first pixel electrode 121 and thesecond pixel electrode 121′ may be minimized.

On the other hand, the organic insulating layer OL may have a secondhole H2 corresponding to the transmission area TA. The second hole H2may be defined by overlapping an opening of the first organic insulatinglayer 116, an opening of the second organic insulating layer 117, and anopening of the third organic insulating layer 118, which are formed tocorrespond to the transmission area TA. These openings may be separatelyformed through separate processes, or may be simultaneously formedthrough the same process. When these openings are formed throughseparate processes, the inner surface of the second hole H2 may not besmooth and may have a step, such as a stair shape.

The second hole H2 may overlap the first hole H1. FIG. 7 illustratesthat the second hole H2 is greater than the first hole H1. According tosome embodiments, the organic insulating layer OL may be provided tocover the edge of the first hole H1 of the inorganic insulating layerIL, so that the area of the second hole H2 is less than the area of thefirst hole H1.

The first organic insulating layer 116 may have a via hole VH1 exposingone of the first source electrode S1 and the first drain electrode D1 ofthe first thin-film transistor TFT, and the first connection electrodeCM may be in contact with the first source electrode S1 or the firstdrain electrode D1 through the via hole VH1 and electrically connectedto the first thin-film transistor TFT. Also, the first organicinsulating layer 116 may have a via hole VH1′ exposing one of the secondsource electrode S2 and the second drain electrode D2 of the secondthin-film transistor TFT′, and the second connection electrode CM′ maybe in contact with the second source electrode S2 or the second drainelectrode D2 through the via hole VH1′ and electrically connected to thesecond thin-film transistor TFT′.

The second organic insulating layer 117 has a via hole VH2 exposing thefirst connection electrode CM, and the third organic insulating layer118 has a via hole VH3 overlapping the via hole VH2. Therefore, thefirst transparent connection electrode TCM may be in contact with thefirst connection electrode CM through the via holes VH2 and VH3. Also,the second organic insulating layer 117 has a via hole VH2′ exposing thesecond connection electrode CM′, and the third organic insulating layer118 has a via hole VH3′ overlapping the via hole VH2′. Therefore, thesecond transparent connection electrode TCM′ may be in contact with thesecond connection electrode CM′ through the via holes VH2′ and VH3′.Therefore, the first pixel electrode 121 may be electrically connectedto the first thin-film transistor TFT through the first transparentconnection electrode TCM and the first connection electrode CM, and thesecond pixel electrode 121′ may be electrically connected to the secondthin-film transistor TFT′ through the second transparent connectionelectrode TCM′ and the second connection electrode CM′.

The first transparent connection electrode TCM and the secondtransparent connection electrode TCM′ may be arranged on the same layeras the first pixel electrode 121 and the second pixel electrode 121′,and may include a transparent conductive oxide. That is, the firsttransparent connection electrode TCM and the second transparentconnection electrode TCM′ may include a conductive oxide, such as indiumtin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium oxide(In₂O₃), indium gallium oxide (IGO), or aluminum zinc oxide (AZO).

The first transparent connection electrode TCM is a member electricallyconnected to the first pixel circuit PC. The first transparentconnection electrode TCM may be a member that electrically connects thefirst pixel electrode 121 of the first organic light-emitting diode OLEDto the first pixel circuit PC. The second transparent connectionelectrode TCM′ is a member electrically connected to the second pixelcircuit PC′. The second transparent connection electrode TCM′ may be amember that electrically connects the second pixel electrode 121′ of thesecond organic light-emitting diode OLED′ to the second pixel circuitPC′.

The first transparent connection electrode TCM and the secondtransparent connection electrode TCM′ may be introduced to reduceinterference between pieces of light reflected from the first pixelelectrode 121 and the second pixel electrode 121′. When a portion of thefirst pixel electrode 121 is in contact with the first connectionelectrode CM through the via holes VH2 and VH3, reflected light may alsobe generated in the via holes VH2 and VH3 by a reflective layer that maybe included in the first pixel electrode 121. The reflected light causeslight interference, and thus, reflective color bands may be visuallyrecognized.

According to some embodiments, the visible recognition of the reflectivecolor bands may be prevented or reduced by introducing the firsttransparent connection electrode TCM and the second transparentconnection electrode TCM′ to minimize reflected light that may begenerated inside the via holes VH2 and VH3.

The first pixel electrode 121 and the second the pixel electrode 121′may include a reflective layer including silver (Ag), magnesium (Mg),aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni),neodymium (Nd), iridium (Ir), chromium (Cr), or any compound thereof.Also, the first pixel electrode 121 and the second pixel electrode 121′may include a conductive oxide, such as ITO, IZO, ZnO, In₂O₃, IGO, orAZO. In this case, the first pixel electrode 121 and the second pixelelectrode 121′ may each have a structure in which a first layer providedas a reflective layer and a second layer including a conductive oxideare stacked in this order. For example, the first pixel electrode 121and the second pixel electrode 121′ may each have a stack structure ofAg/ITO.

The first pixel electrode 121 may be arranged on the same layer as thefirst transparent connection electrode TCM. Also, the first pixelelectrode 121 may cover the edge of the first transparent connectionelectrode TCM and may be in contact with the first transparentconnection electrode TCM. Similarly, the second pixel electrode 121′ maybe arranged on the same layer as the second transparent connectionelectrode TCM′. Also, the second pixel electrode 121′ may cover the edgeof the second transparent connection electrode TCM′ and may be incontact with the second transparent connection electrode TCM′.

The pixel defining layer 119 may cover the edge of each of the firstpixel electrode 121 and the second pixel electrode 121′ on the organicinsulating layer OL, and may include a first opening OP1 and a secondopening OP2 respectively exposing the central portions of the firstpixel electrode 121 and the second pixel electrode 121′. The size andshape of the emission areas of the organic light-emitting diodes OLEDand OLED′, that is, the main sub-pixel Pm and the auxiliary sub-pixelPa, are defined by the first opening OP1 and the second opening OP2.

The pixel defining layer 119 may prevent or reduce instances of anelectric arc or the like occurring on the edges of the pixel electrodes121 and 121′ by increasing the distance between the edges of the pixelelectrodes 121 and 121′ and an opposite electrode 123 on the pixelelectrodes 121 and 121′. The pixel defining layer 119 may include anorganic insulating material, such as polyimide, polyamide, acrylicresin, BCB, HMDSO, and phenol resin, and may be formed by spin coating.

In some embodiments, the pixel defining layer 119 may include a lightblocking material. That is, the pixel defining layer 119 may include aninsulating material (e.g., an organic insulating material) including ablack pigment or dye. As described above, the pixel defining layer 119provided as a light blocking layer may improve visibility by preventingor reducing color mixing between adjacent pixels.

The pixel defining layer 119 may include a third hole H3 in thetransmission area TA. The third hole H3 may overlap the first hole H1and the second hole H2. The light transmittance in the transmission areaTA may be improved by the first to third holes H1 to H3. A portion ofthe opposite electrode 123 to be described below may be arranged on theinner surfaces of the first to third holes H1 to H3.

A first emission layer 122 and a second emission layer 122′ respectivelycorresponding to the first pixel electrode 121 and the second pixelelectrode 121′ are arranged inside the first opening OP1 and the secondopening OP2 of the pixel defining layer 119. The first emission layer122 and the second emission layer 122′ may include a high molecularweight material or a low molecular weight material, and may emit redlight, green light, blue light, or white light.

An organic functional layer may be located above and/or below the firstemission layer 122 and the second emission layer 122′. The organicfunctional layer may be located below the first emission layer 122 andthe second emission layer 122′. In this case, the organic functionallayer may be a hole transport layer (HTL) having a single-layerstructure. Alternatively, the organic functional layer may include ahole injection layer (HIL) and an HTL.

Alternatively, the organic functional layer may be located on the firstemission layer 122 and the second emission layer 122′. In this case, theorganic functional layer may include an electron transport layer (ETL)and/or an electron injection layer (EIL). The organic functional layermay be integrally formed as a single body so as to correspond to theorganic light-emitting diodes OLED and OLED′ respectively included inthe first display area DA1 and the second display area DA2.

The opposite electrode 123 is located on the first emission layer 122and the second emission layer 122′. The opposite electrode 123 mayinclude a conductive material having a low work function. For example,the opposite electrode 123 may include a (semi)transparent layerincluding silver (Ag), magnesium (Mg), aluminum (Al), platinum (Pt),palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir),chromium (Cr), lithium (Li), calcium (Ca), or any alloy thereof.Alternatively, the opposite electrode 123 may further include a layerincluding ITO, IZO, ZnO, or In₂O₃ on the (semi)transparent layerincluding the material described above. The opposite electrode 123 maybe integrally formed as a single body so as to correspond to the organiclight-emitting diodes OLED and OLED′ respectively included in the firstdisplay area DA1 and the second display area DA2.

The layers from the first pixel electrode 121 to the opposite electrode123 in the first display area DA1 may constitute the first organiclight-emitting diode OLED. The layers from the second pixel electrode121′ to the opposite electrode 123 in the second display area DA2 mayconstitute the second organic light-emitting diode OLED′.

A capping layer including an organic material may be located on theopposite electrode 123. The capping layer may be a layer provided toprotect the opposite electrode 123 and increase light extractionefficiency. The capping layer may include an organic material having arefractive index higher than that of the opposite electrode 123.

The opposite electrode 123 may include a transmission hole TAHcorresponding to the transmission area TA. When the transmission holeTAH corresponds to the transmission area TA, it may be understood thatthe transmission hole TAH overlaps the transmission area TA. FIG. 7illustrates that the area of the transmission hole TAH is greater thanthe area of the first hole H1 defined in the inorganic insulating layerIL. However, the disclosure is not limited thereto. According to someembodiments, the area of the transmission hole TAH may be greater thanor equal to the area of the first hole H1.

Due to the transmission hole TAH, a portion of the opposite electrode123 is not present in the transmission area TA, which may significantlyincrease the light transmittance in the transmission area TA. Theopposite electrode 123 having the transmission hole TAH may be formed byvarious methods. According to some embodiments, a material for formingthe opposite electrode 123 is formed on the entire surface of thesubstrate 100, and a portion corresponding to the transmission area TAis removed through laser lift-off to form the opposite electrode 123having the transmission hole TAH. According to some embodiments, theopposite electrode 123 having the transmission hole TAH may be formedthrough metal self-patterning (MSP). According to some embodiments, theopposite electrode 123 having the transmission hole TAH may be formed bya process of depositing the opposite electrode 123 using a fine metalmask (FMM).

The bottom metal layer BML of the second display area DA2 may beprovided to correspond to the entire second display area DA2. In thiscase, the bottom metal layer BML may include a lower hole BMLHoverlapping the transmission area TA. In some embodiments, the shape andsize of the transmission area TA may be defined by the shape and size ofthe lower hole BMLH.

A thin-film encapsulation layer TFEL may be located on the organiclight-emitting diodes OLED and OLED′ of the display panel 10 as asealing member. That is, the organic light-emitting diodes OLED andOLED′ may be sealed by the thin-film encapsulation layer TFEL. Thethin-film encapsulation layer TFEL may be located on the oppositeelectrode 123. The thin-film encapsulation layer TFEL may prevent orreduce infiltration of external moisture, contaminants, or foreignmaterial into the organic light-emitting diodes OLED and OLED′.

The thin-film encapsulation layer TFEL may include at least oneinorganic encapsulation layer and at least one organic encapsulationlayer. In this regard, FIGS. 6 and 7 illustrate a structure in which thethin-film encapsulation layer TFEL includes a first inorganicencapsulation layer 131, an organic encapsulation layer 132, and asecond inorganic encapsulation layer 133, which are stacked. Accordingto some embodiments, the number of organic encapsulation layers and thenumber and stacking order of inorganic encapsulation layers may bechanged.

The first inorganic encapsulation layer 131 and the second inorganicencapsulation layer 133 may include at least one inorganic insulatingmaterial selected from silicon oxide (SiO_(x)), silicon nitride(SiN_(x)), silicon oxynitride (SiON), aluminum oxide (Al₂O₃), titaniumoxide (TiO₂), tantalum oxide (Ta₂O₅), and hafnium oxide (HfO₂), and maybe formed by chemical vapor deposition (CVD). The organic encapsulationlayer 132 may include a polymer-based material. The polymer-basedmaterial may include an acrylic resin, an epoxy resin, polyimide,polyethylene, and the like.

The first inorganic encapsulation layer 131, the organic encapsulationlayer 132, and the second inorganic encapsulation layer 133 may beintegrally formed as a single body so as to cover the first display areaDA1 and the second display area DA2. Accordingly, the first inorganicencapsulation layer 131 and the organic encapsulation layer 132 may bearranged inside the first hole H1 of the inorganic insulating layer IL.

FIGS. 8 and 9 are cross-sectional views illustrating a portion of adisplay device, according to embodiments. For example, FIGS. 8 and 9illustrate a second pixel electrode 121′ and a second transparentconnection electrode TCM′.

According to some embodiments, the second pixel electrode 121′ may havea multilayer structure. For example, as illustrated in FIG. 8 , thesecond pixel electrode 121′ may be provided by stacking a first layer121′a and a second layer 121′b.

The first layer 121′a may include a reflective layer including silver(Ag), magnesium (Mg), aluminum (Al), platinum (Pt), palladium (Pd), gold(Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), or anycompound thereof.

The second layer 121′b may include a conductive oxide such as ITO, IZO,ZnO, In₂O₃, IGO, or AZO. For example, the second layer 121′b may includeITO.

A thickness t2 of the second pixel electrode 121′ may be about 1,000 Åto 1,500 Å. A thickness of the first layer 121′a may be about 800 Å to1,200 Å. A thickness of the second layer 121′b may be about 80 Å to 150Å. That is, the thickness of the second layer 121′b may be less than thethickness of the first layer 121′a.

The second transparent connection electrode TCM′ may be connected to asecond connection electrode CM′ through via holes VH2′ and VH3′ of athird organic insulating layer 118 and a second organic insulating layer117. The second transparent connection electrode TCM′ may include aconductive oxide such as ITO, IZO, ZnO, In₂O₃, IGO, or AZO. Asillustrated in FIG. 8 , a thickness t1 of the second transparentconnection electrode TCM′ may be less than the thickness t2 of thesecond pixel electrode 121′. However, the disclosure is not limitedthereto. The thickness t1 of the second transparent connection electrodeTCM′ may be equal to or similar to the thickness t2 of the second pixelelectrode 121′. For example, the thickness t1 of the second transparentconnection electrode TCM′ may be about 1,000 Å to 1,500 Å.

Because the second transparent connection electrode TCM′ does notinclude a reflective layer, light reflected from the second transparentconnection electrode TCM′ arranged in the via holes VH2′ and VH3′ may beminimized and interference due to the reflected light may be reduced.

On the other hand, referring to FIG. 9 , the second pixel electrode 121′may further include a third layer 121′c located under the first layer121′a. The third layer 121′c may be integrally formed as a single bodyalong with the second transparent connection electrode TCM′. That is,the third layer 121′c of the second pixel electrode 121′ may extend tofunction as the second transparent connection electrode TCM′. In thiscase, because the second pixel electrode 121′ is flat as a whole withouta portion in which a step is formed, interference between pieces oflight reflected from the second pixel electrode 121′ may be furtherreduced.

FIG. 10 is a plan layout diagram illustrating an auxiliary sub-pixel Paof a display device, according to some embodiments.

Referring to FIG. 10 , at least a portion of a second pixel electrode121′ of the auxiliary sub-pixel may have a round shape. According tosome embodiments, the second pixel electrode 121′ may have asubstantially circular shape, as illustrated in FIG. 10 . Because thesecond pixel electrode 121′ has a round shape, angled corners outsidethe second pixel electrode 121′ in a second display area DA2 are reducedor removed. Therefore, deterioration of display quality due todiffraction of reflected light may be prevented, reduced, or minimized.

A second transparent connection electrode TCM′ may be arranged on oneside of the second pixel electrode 121′. The second transparentconnection electrode TCM′ may be located under the second pixelelectrode 121′, and an end of the second pixel electrode 121′ may coverat least a portion of the second transparent connection electrode TCM′.At least a portion of the second transparent connection electrode TCM′may have a round shape.

The second transparent connection electrode TCM′ may be connected to asecond connection electrode CM′ located on another layer through viaholes VH2′ and VH3′. The second transparent connection electrode TCM′and the via holes VH2′ and VH3′ may not overlap a second opening OP2 ofa pixel defining layer 119′ defined as an emission area EA. This isbecause, when the second transparent connection electrode TCM′ and thevia holes VH2′ and VH3′ overlap the emission area EA, the flatness ofthe emission area EA may be lowered and the color may be distorted.

The pixel defining layer 119′ defining the emission area EA may belocated on the second pixel electrode 121′. The emission area EA may bedefined by the second opening OP2 exposing the central portion of thesecond pixel electrode 121′. At least a portion of the emission area EAof the pixel defining layer 119′, that is, the second opening OP2, mayhave a round shape. For example, the second opening OP2 may have asubstantially circular shape, as illustrated in FIG. 9 .

Because the pixel defining layer 119′ includes a light blockingmaterial, the pixel defining layer 119′ may function as a black matrix.That is, the pixel defining layer 119′ may prevent, reduce, or minimizelight passing through the second display area DA2 from being diffractedthrough the edge of the second pixel electrode 121′.

In FIGS. 8 to 10 , the description has been made based on the secondpixel electrode 121′ arranged in the second display area DA2, but thefirst pixel electrode 121 arranged in the first display area DA1 mayalso have the same characteristics as the second pixel electrode 121′.For example, at least a portion of the edge of the first pixel electrode121 (see FIG. 6 ) may have a round shape. Also, the first pixelelectrode 121 may have a three-layer structure, and one of the threelayers may be integrally formed as a single body along with the firsttransparent connection electrode TCM.

FIGS. 11A to 11D are cross-sectional views sequentially illustrating amethod of manufacturing a display panel, according to some embodiments,and schematically illustrate a portion of a second display area.

Referring to FIG. 11A, a second connection electrode CM′ is formed on afirst organic insulating layer 116. The first organic insulating layer116 may be formed by using a spin coating process, a printing process,or the like.

The second connection electrode CM′ may be formed by forming a metaland/or an alloy by using a sputtering process, a vacuum depositionprocess, a CVD process, a pulsed laser deposition process, a printingprocess, or an atomic layer deposition process, and then patterning themetal and/or the alloy by using an etching process.

Referring to FIG. 11B, a second organic insulating layer 117 is formedon the second connection electrode CM′. In this case, the second organicinsulating layer 117 is formed to have a via hole VH2′ partiallyexposing the second connection electrode CM′. After a photosensitivematerial is formed by using a spin coating process or a printingprocess, the via hole VH2′ may be formed in the second organicinsulating layer 117 through an exposure process using a mask.

A third organic insulating layer 118 is formed on the second organicinsulating layer 117. The third organic insulating layer 118 may beformed to have a via hole VH3′ overlapping the via hole VH2′ of thesecond organic insulating layer 117. Accordingly, a portion of thesecond connection electrode CM′ may be exposed by the via hole VH2′ ofthe second organic insulating layer 117 and the via hole VH3′ of thethird organic insulating layer 118.

Referring to FIG. 11C, a second transparent connection electrode TCM′ isformed on the third organic insulating layer 118. The second transparentconnection electrode TCM′ may be connected to the second connectionelectrode CM′ through the via hole VH2′ of the second organic insulatinglayer 117 and the via hole VH3′ of the third organic insulating layer118.

The second transparent connection electrode TCM′ may be formed by usinga transparent conductive material. The second transparent connectionelectrode TCM′ may be formed by forming a transparent conductivematerial by using a sputtering process, a vacuum deposition process, aCVD process, a pulsed laser deposition process, a printing process, oran atomic layer deposition process, and then patterning the transparentconductive material by using an etching process.

Referring to FIG. 11D, a second pixel electrode 121′ is formed on thethird organic insulating layer 118 to cover the end of the secondtransparent connection electrode TCM′.

The second pixel electrode 121′ may be formed by using a reflectivematerial. For example, the second pixel electrode 121′ may include Ag,Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Yb, or Ca. The materialsdescribed above may be used alone or in combination. Also, the secondpixel electrode 121′ may be formed in a single-layer structure or amultilayer structure including the metal and/or the alloy describedabove. In some embodiments, the second pixel electrode 121′ is areflective electrode and may include an Ag/ITO structure.

The second pixel electrode 121′ may be formed by using a sputteringprocess, a vacuum deposition process, a CVD process, a pulsed laserdeposition process, a printing process, or an atomic layer depositionprocess. The second pixel electrode 121′ may be patterned for eachsub-pixel.

As such, because the second pixel electrode 121′ is connected to thesecond connection electrode CM′ or the second pixel circuit PC′ (seeFIG. 7 ) through the second transparent connection electrode TCM′ thatdoes not include a reflective material, reflective color bands caused byreflected light may be significantly reduced.

As described above, because the display panel and the electronicapparatus according to the embodiments include the transparentconnection electrode connected to the pixel electrode on the same layeras the pixel electrode, reflective color bands may be reduced.

It should be understood that embodiments described herein should beconsidered in a descriptive sense only and not for purposes oflimitation. Descriptions of features or aspects within each embodimentshould typically be considered as available for other similar featuresor aspects in other embodiments. While one or more embodiments have beendescribed with reference to the figures, it will be understood by thoseof ordinary skill in the art that various changes in form and detailsmay be made therein without departing from the spirit and scope asdefined by the following claims, and their equivalents.

What is claimed is:
 1. An electronic apparatus comprising: a displaypanel comprising a first display area, in which a first display elementis arranged, and a second display area, in which a second displayelement and a transmission area are arranged; and a component on a lowersurface of the display panel and overlapping the second display area,wherein the display panel comprises: a substrate; a second pixel circuiton the substrate and electrically connected to the second displayelement, the second pixel circuit comprising at least one thin-filmtransistor; an organic insulating layer covering the at least onethin-film transistor; and a second transparent connection electrode onthe organic insulating layer in the second display area and electricallyconnected to the second pixel circuit, wherein the second displayelement comprises a second pixel electrode on a same layer as the secondtransparent connection electrode.
 2. The electronic apparatus of claim1, wherein the second pixel electrode includes a reflective material. 3.The electronic apparatus of claim 1, wherein the second pixel electrodecovers one end of the second transparent connection electrode.
 4. Theelectronic apparatus of claim 1, wherein the second pixel electrodecomprises a first layer and a second layer on the first layer, the firstlayer including a reflective material and the second layer including atransparent conductive material.
 5. The electronic apparatus of claim 1,wherein the second transparent connection electrode is inside a via holedefined in the organic insulating layer.
 6. The electronic apparatus ofclaim 1, wherein the second pixel electrode comprises a first layerincluding a reflective material and a third layer under the first layer,and the third layer is integral with the second transparent connectionelectrode.
 7. The electronic apparatus of claim 1, wherein at least aportion of an edge of the second pixel electrode has a round shape. 8.The electronic apparatus of claim 1, further comprising a pixel defininglayer having an opening exposing a center of the second pixel electrodeand covering an edge of the second pixel electrode, wherein the pixeldefining layer includes a light blocking material.
 9. A display panelcomprising: a substrate; a first display element on the substrate; afirst pixel circuit on the substrate and electrically connected to thefirst display element, the first pixel circuit comprising at least onethin-film transistor; an organic insulating layer covering the at leastone thin-film transistor; and a first transparent connection electrodeon the organic insulating layer and electrically connected to the firstpixel circuit, wherein the first display element comprises a first pixelelectrode on a same layer as the first transparent connection electrode.10. The display panel of claim 9, wherein the first pixel electrodecomprises a first layer and a second layer on the first layer, the firstlayer including a reflective material and the second layer including afirst transparent conductive material, and the first transparentconnection electrode includes a second transparent conductive material.11. The display panel of claim 9, wherein the first transparentconnection electrode covers one end of the first pixel electrode. 12.The display panel of claim 9, wherein the organic insulating layer isprovided by sequentially stacking a first organic insulating layer, asecond organic insulating layer, and a third organic insulating layer,and the first transparent connection electrode is connected to a firstconnection electrode on the first organic insulating layer through a viahole.
 13. The display panel of claim 12, wherein the third organicinsulating layer includes a siloxane-based organic material.
 14. Thedisplay panel of claim 9, wherein at least a portion of an edge of thefirst pixel electrode has a round shape.
 15. The display panel of claim9, further comprising a pixel defining layer having an opening exposinga center of the first pixel electrode and covering an edge of the firstpixel electrode, wherein the pixel defining layer includes a lightblocking material.
 16. A method of manufacturing a display panel, themethod comprising: forming a first pixel circuit comprising at least onethin-film transistor on a substrate; forming a first organic insulatinglayer covering the at least one thin-film transistor; forming a secondconnection electrode on the first organic insulating layer; forming asecond organic insulating layer and a third organic insulating layercovering the second connection electrode and having a via hole exposinga portion of the second connection electrode; forming a secondtransparent connection electrode on the third organic insulating layerand connected to the second connection electrode through the via hole;and forming a second pixel electrode on the third organic insulatinglayer and covering one end of the second transparent connectionelectrode.
 17. The method of claim 16, wherein the second pixelelectrode includes a reflective material.
 18. The method of claim 16,wherein the second pixel electrode comprises a first layer and a secondlayer on the first layer, the first layer including a reflectivematerial and the second layer including a transparent conductivematerial.
 19. The method of claim 16, wherein at least a portion of anedge of the second pixel electrode has a round shape.
 20. The method ofclaim 16, further comprising forming a pixel defining layer having anopening exposing a center of the second pixel electrode and covering anedge of the second pixel electrode, wherein the pixel defining layerincludes a light blocking material.